Machine and process for making wrapped corrugated boards



Marchy 7, 1967 FQ'MARTIN, sR

MACHINE AND PROCESS FOR MAING WRAFPED CORRUGATED BOARDS -Fil'ed Feb. 5, 1963 5 Sheets-Sheet l .Wil

14% Wamxf., 951552.51! r JNVENTOR. HARRY F. MARTIN,

nimh/vnf Mafch 74, v 1967 H. Fg MARTIN, SIR

MACHINE AND PROCESS FOR MAKING WRAPPED CORRUGATED BOARDS Sheets-Sheet Filed Feb. '5, 1963 IN V EN TOR. F. my,

RIYf/f vMami] 7,. 1961 ,Y .H. F. MARTIN, sR 3,302995 MACHINE-AND PRocEss FOR MAKING WRAPPEDCORRUGATED BOARDS Filed Feb. 5; 1965 5 Sheets-Sheet 3 INVENTOR. HAR F. MARTIN, sr,

/ BY @ma M United States Patent 3,307,995 MACHINE AND PROCESS FOR MAKING WRAPPED CORRUGATED BOARDS Harry F. Martin, Sr., Alamo, Calif., assignor to Weyerhaeuser Company, Tacoma, Wash., a corporation of Washington Filed Feb. 5, 1963, Ser. No. 256,434 16 Claims. (Cl. 156-216) This invention pertains to the making of double-faced corrugated board in which one or both of two opposite edges are wrapped and more particularly, it pertains to machines and methods of making such board.

A primary object of the invention is to provide a machine for the at least partly concurrent manufacture of a plurality of strips of double-faced corrugated board each having one of its edges wrapped.

Another primary object of the invention is to provide a machine for such production of double-faced corrugated board strips each of which has both of two opposite edges wrapped.

A further object is to provide a machine for such production of at least three double-faced corrugated board strips each having one or both of two opposite edges wrapped.

Another object of importance is to produce the above strips on a standard corrugated facing machine .with the use of certain inexpensive and easily mountable attachments.

A further and more specific object of the invention is to produce the strips as indicated in any of the rst three objects by a machine in which a single face of corrugated sheet is severed into a plurality of singlefaced strips and the latter spread laterally apart predeterminately whereupon a single facing sheet is secured and spaced apart to the strips in a predetermined rela- 'tion therewith forming double-faced strips connected by the sheet and the latter subsequently severed -so as to produce separate double-faced strips having one or two laterally extending portions of what had been said single-facing sheet prior to the severing thereof, after which the latter extendiing portions of the strips are folded over and secured, thus producing double-faced strips having one or two wrapped edges each, as desired.

Still another object is to provide a machine for the production of the strips as indicated in any of the first three objects and by a machine as indicated in the preceding object in which unique single-faced strips spreading and spacing control means are employed.

Yet another object is to accomplish the objective set forth in the preceding paragraph in which machine the y strip spreading means comprises first means for partly spreading the strips and second means for spreading the strips at least slightly further to a substantially predetermined lateral spacing of each strip from the one or ones adjacent to it thereby establishing or assuring proper spacing between the strips.

A still further and important object is to accomplish the objects set forth in each of the preceding paragraphs which machine is adjustable so as to handle and process single-faced corrugated sheets of different widths and second or single facing sheets of different widths and moreover, so as to produce at least partly currently different numbers of double-faced wrapped strips for different adjustments thereof.

Another primary object of the invention is to provide a novel method of or process for making a plurality of strips of double-faced corrugated board each having one or both of two opposite edges thereof wrapped, said method or process in its various forms and aspects being apart and distinct from the machine indicated in any of the above objects and the one disclosed hereinafter Patented Mar. 7, 1967 n detail inasmuch as such method or process in its various forms may be practiced by the use of hand tools or by machines or equipment other than as so indicated in the objects and detail disclosure.

Other objects, advantages and features of the invention will appear upon proceeding with the following illustrative description, read in conjunction with the accompanying drawing, in which:

FIGURES l and 2, taken together and in sequence, constitute a vertical longitudinal sectional view of a preferred form of machine of the invention, broken in the middle and shown in two parts for convenience of illustration, the machine also being shown broken from adjoining structure at the front and rear thereof and additionally being shown broken at a number of places within the View for the purpose of shortening the view; and

FIGURES 3, 4 and 5, .taken together and in sequence, constitute a perspective view of the machine of FIGURES l and 2, broken in two places and shown in three parts for convenience Vof illustration and so as to better disclose the machine, the machine also being shown broken from adjoining structure at the front and rear thereof and additionally being shown broken away in places so as to better disclose the machine.

The machine is shown in operation with material passing continuously therethrough and being processed into three strips of double-faced corrugated board each of which has its opposite longitudinal edges wrapped.

Referring to the drawing views in detail, the numeral 1 generally designates a sheet of wide single-faced corrugated material, consisting of an upper facing sheet 2 and a lower sheet 3 of corrugated material of the same width as that of sheet 2 and suitably secured to the sheet by adhesive in the customary manner, which enters the machine over a tensioning roll 5. The sheet of wide single-faced corrugated material 1 is then severed by slitting by stationary knives 7 into three narrower sheets or strips or single-face corrugated material 9, 10 and 11 of the same width as the sheet 11 moves continuously past the knives towards the right as seen in the drawing views. The three strips of single-faced corrugated material next pass under a tensioning roll 13 and over the smaller rolls 14 and 15 associated with the latter. The tensioning r-olls 5 and 13 hold the corrugated material taut as it passes through the slitting station at 7. After the three strips of single-faced corrugated `material 9, 10 and 11 leave the tensioning roll 13, they come in contact with stationary pressure bars 17, 18 and 19 respectively. These bars extend laterally across the major extent of and [bear against the upper surfaces of the respective strips applying pressure to the s ame for a purpose which will ybe explained. These bars, as can be seen from the drawing, are each centered in a lateral direction with respect to the respective strips. The center bar 18 extends and bears against the center strip 10 in a straight line which is normal or at right angles to the longitudinal direction of travel of the sheet 1 prior to severing thereof into strips and of the center strip 10 after this severing. Such bearing against and pressure exerted on the surface of the center strip at right angles as indicated, cause this strip to be pulled along perfectly straight from the roller 15 and from the bar 18 to assure straight rearward movement of the center strip with no change of lateral position.

.The outer bars 17 and 19, on the hand, are not normal to the above-mentioned direction, but rather extend and outer bars are exactly equal and opposite each other, each being inclined rearwardly and outwardly relative to the center bar 18. The inner limits of the ybars 17 and 19 are also in transverse alignment with the center bar while the opposite outer ends -of these bars are rearwardly therefrom. The outer bars 17 and 19 and also the inner bar 18 also preferably extend and bear against the respective srtips so that the theoretical or geometrical elements of each strip extending thereacross normal or at right angles to the longitudinal edges of the respective strips are horizontal, that is the bars do not cause the strips to be twisted but the latter remain with their transverse elements still horizontal after passing under the bars.

By the angle of extension and bearing of the outer bars 17 and 19, the outer strips 9 and 11 are pulled straight or normal from or past the bars but at an youtward angle each relative to the roll and the center strip 10 thereby causing the outer strips to move laterally away from the center strip as they are pulled longitudinally along such outward lateral movement of the outer strips being at equal rates because of the equal and opposite inclinations of the outer bars 17 and 19. Thus, the strips into which the sheet 1 is divided are caused to be spread out from each other and equally so on each side.

The spread apart single-faced corrugated strips 9, 10 and 11 next pass beneath a tensioning roll 21 and then over a pair of rolls 22 and 23 which apply glue on the exposed edges of the corrugated material of each strip. The roll 23 is part of a standard type of gluing apparatus as can be seen from the drawing.

After having glue applied thereto, the strips 9, 10 and 11 pass by stationary separation control triangles 25 which further separate or spread the strips from each other at least slightly to establish and thereby assure predetermined separation or spacing of the strips from each other. It is preferred that the srtips 9, 10 and 11 be spaced and the actual machine shown spaces the strips 2 inches apart, although this can be varied by the use different control triangles or of adjustable triangles or control means. As can be seen from the drawing, these control triangles are positioned between the strips 9, 10 and 11 bearing against certain longitudinal edges thereof in contrast to the previous separator or spreader means 17, 18 and 19.

A rolled sheet of facing material 29 is rotatably supported directly -beneath the roll 13, the unrolled portion of the sheet 29 being trained over and under a number of rolls, 30 through 33, and then brought into light contact with the underside of the corrugated material of the predeterminately spaced apart strips 9, 10' and 11, to which glue has ybeen applied, by passing between pressure rolls 35 and 36 together with the strips 9, 10 and 11, as clearly shown in the drawing. The single-faced strips and the facing sheet 29 are accordingly affixed or secured together by the glue as the same are moved continuously along by a severed friction belt 38 over a series of heated bars 39 which set the adhesive and through a cooling section therebeyond between bolt 38 along the top and a belt 4t) therebelow, which between them apply pressure to the newly formed `double-faced strips 43, 44 and 45.

The double-faced corrugated strips just described as formed, of course, are joined or interconnected at the 'bottom by the single-facing sheet 29 which is secured by the `adhesive to each of what had been the separate and spaced apart single-faced strips thus forming the double-faced strips. The facing sheet 29, as should be apparent, is considerably wider than the sheet of single-faced material 1 prior to severing thereof into strips and spreading of the latter and moreover the sheet 29 is of such a width as to not only extend under or span the spaced strips 9, 10 and 11 while being secured thereto but additionally extend -laterally outward beyond the outer strips an amount or distance -on each side which is at least substantially equal to one half the distance separating the adjacent singlefaced strips prior to their being secured to the facing sheet and the adjacent double-faced strips thereafter.

The sheet 29 actually depicted in the drawing is of such a width and is so applied by the machine as t0 extend outwardly one inch beyond each of the outer strips on each side of the sheet 29 which is one half the 2-inch spacing between each of the adjacent strips.

The interconnected or joined double-faced strips 43, 44 and 45 after being formed pass along under overhead glue pots 48 of conventional construction which apply continuous strips of glue to the strips 43, 44 and 45 along both longitudinal edges of each of the strips. These gluing devices 0r pots as can be observed from the drawing, each have a wheel which turns as the respective strips pass thereunder for the application of the adhesive.

The strips 43, 44 and 45 next pass along through rotary knives 50 which are laterally positioned on the machine so as to sever the interconnecting single-facing sheet 29 midway between the adjacent strips 43 and 44 and adjacent strips 44 and 45 thus to separate the strips from each other, that is to form or produce separate double-faced strips.

It will be noted that after separation of the strips, 43, 44 and 45 by the severing just described each strip has or is provided with two portions of what had been the single-facing sheet 29 prior to the severing thereof extending laterally beyond each of the longitudinal edges of the strip respectively and along the length of these edges respectively and as previously indicated that these portions extend substantially equal amounts or distances beyond the respective edges inwardly, 1 inch in the actual strips depicted. Additional rotary knives 52 are provided to trim the outwardly extending portions of the lower face of the outer strips 43 and 45 if necessary so as to make sure that these portions do not extend more than the above noted half the distance between adjacent strips or putting it another way, so as to be assured that they do not extend outwardly more than the other extending portions of outer strips extend inwardly.

The separate double-faced strips 43, 44 and 45 each with two portions of its lower face extending beyond the longitudinal edges thereof respectively, as noted, move past stationary wrapping means 54 and 55 which engage the extending face portions of each strip moving or folding them upwardly so as to be in engagement with and also extend beyond the edges.

Then further folding the upwardly extending portions inwardly over and into tight engagement with the marginal or edge portions of the upper face of the strip along which glue had been applied by the glue pots 48, thereby to produce two wrapped edges on each strip. The wrapping means are essentially angle irons which have been uniformly twisted so that the two legs of each of the irons are horizontal and vertical where an extending face portion enters the same while the same legs become vertical and horizontal, respectively, where the strip leaves the iron with the horizontal portion of the iron extending inwardly over the upper face of the strip. 54 are single wrapping means for operating on a single extending face portion while 55 are double wrapping means for operating on two adjacent and oppositely extending face portions, the latter means being essentially two twisted angle irons in back-to-back relation at the front thereof.

The separate double-faced strips 43, 44 and 45 now with both longitudinal edges of each strip wrapped, as above described, continue along beyond the wrapping means and under rotatable creasing or scoring rolls 58 which place longitudinal creases or score lines in the material between the sidewalls and the upper and lower flaps of a completed corrugated carton along which the aps are folded inwardly. The continuously creased or scored strips continue along between rotating cut-olf knives 60 which cut the single continuous strips 43, 44 and 45 into shorter strips or pieces as for instance 62, 63 and 64 in the drawings, from each of which a carton is constructed having wrapped end edges on all of the flaps. A belt conveyor 66, shown fragmentarily carries the shorter strips or pieces on for further processing into cartons.

Returning to the spreading means 17, 18 and 19, these are adjustably mounted on a stationary cross support 68 having slots 70 therein within which slots the supporting shank or rod-like portions 72 can be moved laterally and tightened or locked in position by the nuts (see FIG. l). The bars 17, 18, 19 can also be turned at the threaded connectors 74 and locked in position by the nuts 75. Such adjustability permits the spreading means to handle and accommodate different widths of single-faced sheets 1 centering on the severed strips formed therefrom and also different numbers of bars 17, 18, 19 may be mounted on the cross member 68 or adjusted in and out of use by rotation at 74 to accommodate different numbers of strips that may be desired to be formed and processed. For instance, the machine may be so adjusted or set up to cut or process two strips or four or more strips rather than the three peresently shown for whatever purpose desired. The position and number of slitting knives 7 control triangles 25, glue pots 48 rotary knives 50, wrapping means 54 and creasing rolls 58 are likewise laterally adjustable and variable in number for accommodating different widths of sheets 1 and 29 and consequently of the strips formed therefrom and being processed and also different numbers of strips desired to be formed and processed in agreement with the adjustment of and the numbers of bars 17, 18 and 19 which are employed.

An indicated in the preamble, the invention also covers a method of process, in various forms and modifications, of making double-faced corrugated boards or strips in which one or both of two opposite edges of each board are wrapped which method or process is apart and distinct from any machine for producing the boards or strips within the purview of the objects in the preamble and from the machine just disclosed in detail.y It was indicated in the preamble that the process or method of making the boards or strips could be practiced or carried out by the use of hand tools and equipment, for instance, or by machines and equipment other than those previously indicated.

The method or process of the invention to which reference has been made may be broadly set forth, as an example, as comprising the steps of severing a single-faced corrugated sheet having a first facing sheet attached to a corrugated sheet, the first face and the corrugated material being of substantially the same width, into a plurality of single-aced strips; spreading the strips laterally apart substantially predeterminately from each other; applying adhesive to the exposed ridges of the corrugated material of the strips; aliixing a second facing sheet to the exposed ridges of the plurality of single-faced strips, the second sheet being wider than the plurality of spaced apart strips and joining the strips together; severing said second sheet between the strips; applying adhesive along or near the edge of the first sheet to each of the double-faced strips; wrapping the extending portion of each of the second sheets around the longitudinal edge of its strip and over the first sheet; and securing said extending portion of the second sheet to the adhesive coated portion of the rst sheet.

As is evident, the first mentioned application of adhesive may be before, after, or even in the course of spreading of the strips and the second mentioned application of adhesive may be before or after the second mentioned severing.

The method or process may also comprise the following steps where precut or formed single-faced strips can be provided, for instance and as an illustration only: affixing a second facing sheet to the corrugated cores of the plurality of single-faced strips with the strips in substantially predetermined spaced apart relation to each other, subsequently severing the second facing sheet so as to produce separate double-faced strips each having one or two extending portionsof the second facing sheet extend- 6 ing laterally beyond one or both of two opposite edges of the strip, and wrapping said edge or edges of each strip with the extending face portion or portions respectively and afixing the previously extending face portion or portions in place after the wrapping as by suitable adhesive.

Regarding machines for producing wrapped doublefaced boards or strips, the first application of adhesive carried out by the machine may also be before, after, or in the course of the spreading of the strips and the second application of adhesive carried out by the machine may also be before or after the second severing.

Although but a single illustrative form of machine has been depicted in the drawing and described in detail in the specification and although certain illustrative methods or processes have likewise been described in the specification, various forms and modifications of machines and of processes or methods of making wrapped corrugated board or strips are possible and had in mind and accordingly the appended claims should be limited only by their terms construed within the broad overall spirit of the invention in its various aspects and concepts.

In the appended claims, use of the word over in connection with t-he laterally extending face portions which are folded over edge portions of the opposite face of each strip during the wrapping process is general and is intended to cover under for example, as well as over in a strict or absolute sense. The word laterally, for example,"employed in the claims, is also not intended to be construed in an absolute or strict sense but rather so as to be relative to the strips or sheets themselves, for example, whatever their position or attitude may be.

What is claimed is:

1. In a machine for producing a plurality of strips of double-faced corrugated board in which at least one longitudinal edge of each strip is wrapped, the combination comprising, l

means for severing a single-faced corrugated sheet having a first face aflixed to a corrugated sheet into a plurality of single-faced strips, means for spreading the strips laterally apart substantially predeterminately from each other, means for applying adhesive to the exposed ridges of the corrugated material of the strips, means for affixing a second facing sheet of greater width than that of the laterally spaced single-faced strips to said strips along the exposed side of the corrugated material of the strips to which the adhesive has been applied so as to produce double-faced strips joined together by said second facing sheet, means for severing said second facing sheet so as to produce a plurality of separate double-faced strips each having a portion of said second facing sheet extending beyond and entirely along one longitudinal edge of the strip, means for applying adhesive to each of the doublefaced strips longitudinally along said first face of the strip near said one longitudinal edge of the strip, and means for wrapping the extending portion of each separate double-faced strip around the longitudinal edge of the strip adjacent thereto and over the portion of said first face having adhesive thereon and for securing said extending portion to said face portion so as to produce a wrapped longitudinal edge on the strip. 2. The subject matter of claim 1 wherein the means for applying adhesive to each of the double-faced strips is located ahead of the means for severing of said second facing sheet.

3. The subject matter of claim 1 wherein the means for spreading the singlefaced strips laterally apart cornprises iirst means for spreading the strips laterally apart from each other and second means for further and predeterminately spreading the strips laterally apart from each other.

4. The subject matter of claim 3 in which said first means for spreading the single-faced strips comprises means for bearing against the face of one of the longitudinally moving single-faced strips and thereby guiding said one strip laterally outwardly away from another strip.

5. The subject matter of claim 3 in which said first means for spreading the single-faced strips comprises means for bearing against the face of one of the longitudinally moving single-faced strips along substantially a straight line which is at an angle to the longitudinal direction of movement of the strip and thereby guiding said one strip laterally outwardly away from another strip.

6. The subject matter of claim 5, said first means for spreading the single-faced strips further including means for bearing against the face of the other single-faced strip along substantially a straight line which is at an angle to the longitudinal direction of movement of the strip and thereby guide the strip laterally outwardly in a direction away from the rst recited longitudinally moving double- Ifaced strip, the angle of inclination of each of said straight lines and of said means therealong being substantially equal and the inclination of each of these lines and means being opposite to each other.

7. The subject matter of claim 3 in which said first means for spreading the single-faced strips comprises means for bearing against the face of one of the singlefaced strips along substantially a straight line 'which is substantially at right angles to the longitudinal direction of movement of the strip before any lateral spreading movement of any of the single-faced strips begins thus assuring continued straight movement of the strip therefrom in said longitudinal direction thereof with substantially no change of lateral position of the strip and means for bearing against the face of another of the single-faced strips adjacent the first recited singlefaced strip along substantially a straight line which is at an angle to said longitudinal direction of movement of the first strip such as to cause the strip to move laterally outwardly away from the first strip as the former strip is moving longitudinally along.

8. The subject matter of claim 3, said second means for spreading the single-faced strips comprising surface means between the strips against which the facing adjacent longitudinal edges of adjacent spaced single-faced strips bear when present and moving longitudinally along causing fulther at least slight spreading of the strips laterally apart from each other such that all of the single-faced strips become substantially predeterminately laterally spaced apart from each other.

9. The subject matter of claim 8, said first means for spreading the single-faced strips comprising means for so bearing against the face of one of the single-faced strips as to cause the strip to move laterally outwardly in a direction away from another strip as the former strip is moving longitudinally along.

10. The subject matter of claim 3, the first named means for applying adhesive being located between said first and second strip spreading means.

11. The subject matter of claim 1, the means for sever- .ing said second facing sheet being aligned with said spreadfing means.

12. The subject matter of claim 11, the means for :spreading the single-faced strips laterally apart comprising first means for spreading the strips laterally apart from yeach other and second means for further and predeter- .minately spreading the strips laterally apart from each other.

13. The method of making strips of double-faced corrugated board in which at least one longitudinal edge of each strip is wrapped comprising the steps of:

severing a single-faced corrugated sheet in which the first face and corrugated material are of substantially the Sam@ Width vinto .a plurality of single-faced strips,

spreading the strips laterally apart substantially predeterminately from each other,

applying adhesive to the exposed ridges of the corrugated material of the strips after formation of the latter by severing,

aflixing a second facing sheet of greater width than the spaced apart strips to the laterally spaced apart strips along the exposed side of the corrugated material of the strips so as to produce double-faced strips joined together by said second facing sheet,

severing said second facing sheet so as to produce a plurality of separate double-faced strips each having a portion of said second facing sheet extending beyond and entirely along one longitudinal edge of the strip,

applying adhesive to each of the double-faced strips longitudinally along said first face near said one longitudinal edge of the strip,

wrapping the extending portion of each separate doublefaced strip around the longitudinal edge of the strip adjacent thereto and over said last-applied adhesive and securing said extending portion of each separate doublefaced strip to said face portion so as to produce a wrapped longitudinal edge on the strip.

14. The subject matter of claim 13, the step of severing said second facing sheet comprising so severing the sheet substantially midway between two adjacent doublefaced strips joined together by the sheet thus producing two separate double-faced strips having the extending portions thereof extending laterally towards each other from the facing adjacent longitudinal edges of the two strips at least immediately after the severing.

15. The method of making strips of double-faced corrugated board in which both longitudinal edges of each strip are wrapped comprising the steps of severing a single-faced corrugated sheet in which the first face and corrugated material are of substantially the same width into a plurality of single-faced strips, spreading the strips laterally apart substantially predeterminately from each other so that the distances between all adjacent strips are substantially equal,

applying adhesive to the exposed ridges of the corrugated material of the strips after formation of the latter by severing,

afiixing a second facing sheet of greater width than the spread-apart strips to the latterally spaced apart strips along the exposed side of the corrugated material of the strips so as to produce double-faced strips joined together by said second facing sheet and so that said second facing sheet extends laterally outwardly beyond the outer longitudinal edge of each outer strip a distance not substantially less than one half the distance separating adjacent strips from each other,

severing said second facing sheet of the joined doublefaced strips substantially midway between all of the adjacent strips so as to produce separate doublefaced strips having a portion of what was said second facing sheet extending laterally from each longitudinal edge of said strip that is facing and adjacent a longitudinal edge of an adjacent strip towards the portion extending from the `facing and adjacent edge of the adjacent strip,

applying adhesive to each of the double-faced strips longitudinally along said first face at least near both longitudinal edges of the strip,

wrapping both extending portions of each of the separate double-faced strips around the longitudinal edges of the strip adjacent thereto respectively and over at least said adhesive along the longitudinal edges of the strip respectively and securing both extending portions of each strip to said face portions thereof respectively Where adhesive has been applied.

16. The method of making strips of double-faced corrugated board in which at least one longitudinal edge of each strip is wrapped comprising the steps of aflixing a plurality of single-faced corrugated strips and a single much wider sheet of facing material together with the strips in substantially predetermined spaced apart relation to each other,

subsequently severing the single facing sheet so as to produce separate double-faced strips of the same number as there were of the single-faced strips each having a portion of what had been the single facing sheet prior to the severing thereof extending laterally beyond one longitudinal edge of the strip and longitudinally therealong,

folding said extending portions around the edges of the double-faced strips adjacent thereto respectively and over at least the marginal edge portions of they opposite faces of the strips respectively adjacent to said longitudinal edges of the double-faced strips respectively,

and

References Cited by the Examiner UNITED STATES PATENTS Feister 156-517 Haren 156-554 Smith 156-202 Smith 156-216 Pfeifer 156-554 Weber 156-292 Lutwack 156-554 Bousquet et al. 161-102 Little 156-210 Boyle 156-517 EARL M. BERGERT, Primary Examiner.

20 W. E. HOAG, Assistant Examiner. 

1. IN A MACHINE FOR PRODUCING A PLURALITY OF STRIPS OF DOUBLE-FACED CORRUGTED BOARD IN WHICH AT LEAST ONE LONGITUDINAL EDGE OF EACH STRIP IS WRAPPED, THE COMBINATION COMPRISING, MEANS FOR SEVERING A SINGLE-FACED CORRUGATED SHEET HAVING A FIRST FACE AFFIXED TO A CORRUGATED SHEET INTO A PLURALITY OF SINGLE-FACED STRIPS, MEANS FOR SPREADING THE STRIPS LATERALLY APART SUBSTANTIALLY PREDETERMINATELY FROM EACH OTHER, MEANS FOR APPLYING ADHESIVE TO THE EXPOSED RIDGES OF THE CORRUGATED MATERIAL OF THE STRIPS, MEANS FOR AFFIXING A SECOND FACING SHEET OF GREATER WIDTH THAN THAT OF THE LATERALLY SPACED SINGLE-FACED STRIPS TO SAID STRIPS ALONG THE EXPOSED SIDE OF THE CORRUGATED MATERIAL OF THE STRIPS TO WHICH THE ADHESIVE HAS BEEN APPLIED SO AS TO PRODUCE DOUBLE-FACED STRIPS JOINED TOGETHER BY SAID SECOND FACING SHEET, MEANS FOR SEVERING SAID SECOND FACING SHEET SO AS TO PRODUCE A PLURALITY OF SEPARATE DOUBLE-FACED STRIPS EACH HAVING A PORTION OF SAID SECOND FACING SHEET EXTENDING BEYOND AND ENTIRELY ALONG ONE LONGITUDINAL EDGE OF THE STRIP, MEANS FOR APPLYING ADHESIVE TO EACH OF THE DOUBLEFACED STRIPS LONGITUDINALLY ALONG SAID FIRST FACE OF THE STRIP NEAR SAID ONE LONGITUDINAL EDGE OF THE STRIP, AND MEANS FOR WRAPPING THE EXTENDING PORTION OF EACH SEPARATE DOUBLE-FACED STRIP AROUND THE LONGITUDINAL EDGE OF THE STRIP ADJACENT THERETO AND OVER THE PORTION OF SAID FIRST FACE HAVING ADHESIVE THEREON AND FOR SECURING SAID EXTENDING PORTION TO SAID FACE PORTION SO AS TO PRODUCE A WRAPPED ONGITUDINAL EDGE ON THE STRIP. 